JPH11108160A - Pulley for chain transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulley for chain transmission which can be rotated while its peripheral surface is contacted with the plates of a chain. SOLUTION: A pulley 6 for chain transmission is driven in such a way that its peripheral surface is contacted with the plates 2A and 2B on the inside or outside of a chain 2 to be run along a running path in endless form. The peripheral surface 6C of the pulley 6 is formed cylindrically, and there is no risk that a sideways swinging is generated in the chain 2 resulting from misalignment of rotary shafts, and when the load applied on the input shaft 7 of an apparatus to be fitted with the pulley 6 increases, a slip is generated between the pulley 6 and plates 2A and 2B so that over-loaded condition can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulley for rolling a relatively light-load device by rolling contact with a transmission chain, and more particularly to an oil pump or a water pump depending on a timing chain used in an engine. The present invention relates to a transmission chain plate contact type pulley suitable for driving an auxiliary machine such as the above.

[0002]

2. Description of the Related Art Conventionally, a timing chain used in an engine of an automobile or the like meshes with a sprocket mounted on an input shaft of an auxiliary machine such as an oil pump or a water pump in a middle of a traveling path of the timing chain, so that a crankshaft of the engine is driven. The rotation drives these accessories.

In this case, when a normal silent chain in which a plate side edge (hereinafter referred to as a back surface) which is a plate outer peripheral side of a plate is formed flat in a timing chain, a sprocket of an auxiliary machine is attached to the chain. There is a problem that the space occupied by the traveling path of the chain becomes large, since it must be arranged entirely on the inner peripheral side of the traveling path.

On the other hand, in order to solve such a problem,
Conventionally, as shown in FIGS. 6 and 7, a double-side mesh type silent chain has been proposed which is capable of meshing with a sprocket on both inner and outer sides of a traveling path of a chain.

FIG. 6 shows a large number of plates 11,
When the silent chain 13 is knitted by connecting the endless endless sprockets 12 to the inner peripheral side or the outer peripheral side thereof,
, And having teeth engaging the sprocket 15 on the opposite side.
Has a constricted center and a pair of chevron-shaped tooth surfaces formed on both sides thereof.

FIG. 7 shows a plate 21 having a pair of chevron-shaped tooth surfaces formed on the inner periphery and having a flat outer periphery.
A plate 22 having a flat inner peripheral side and a pair of mountain-shaped tooth surfaces formed on an outer peripheral side is alternately connected by pins 23 to form an endless silent chain 24, and the inner periphery of the silent chain 24 is formed. The teeth of the plates 21 and 22 are individually meshed with the teeth of two pitches formed on the sprocket 25 meshing on one side of the outer side or the outer peripheral side and the sprocket 26 meshing on the other side. It is adapted.

[0007]

The use of a double-side mesh type silent chain, as described above, capable of meshing with a sprocket on both the inner circumferential side and the outer circumferential side, as a timing chain for an automobile engine. The sprocket and idle sprocket for driving auxiliary equipment mesh with the outer periphery of the chain running path on the tight side, so that the outgoing side path can be as close as possible to the return side path. There is an advantage that the space occupied by the traveling path can be reduced, but since a chevron-shaped tooth surface for meshing with the teeth of the sprocket is formed on the back side of the plate, shoe surfaces such as a tensioner and a chain guide are formed. There is a problem that it is difficult to make the sliding contact with the back surface of the plate.

In other words, if there is a mountain-shaped tooth surface on the back side of the plate, the tip of the plate contacts the shoe surface intermittently, so that the shoe surface is severely worn and its durability life is shortened. There is a problem that the anti-vibration effect is weakened due to the electrical contact, and it becomes a source of chain elongation and noise.

Further, since the center of the plate is constricted, the cross-sectional area at the center of the plate is small, and the mechanical strength is significantly reduced. When the plate thickness is increased to secure the strength, the width of the chain becomes large. In addition, there is a problem that the weight increases.

Also, in the case of meshing with the teeth of the sprocket at two pitch intervals as shown in FIG. 7 described above, since the amplitude of the polygonal motion when the silent chain meshes with the sprocket is large, a smooth high-speed transmission is performed. Cannot be performed, and the sprocket wears early.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide a pulley for a chain transmission device that can be driven to rotate by bringing an outer peripheral surface into contact with a plate of a chain.

[0012]

In order to achieve the above object, a chain driving pulley according to the present invention is provided in contact with a side edge of a plate of the chain on an inner peripheral side or an outer peripheral side of a chain driven endlessly. It has a cylindrical outer peripheral surface that is driven to rotate. It is preferable that the cylindrical outer peripheral surface is formed of a material that can be elastically deformed by a contact pressure received from a plate.

Further, the plate contact type pulley for a power transmission chain according to the present invention is a positive pulley which is rotationally driven in contact with the flat plate side edge of the chain on the inner or outer peripheral side of the endlessly circulated chain. It has a polygonal columnar outer peripheral surface.

[0014]

According to a first aspect of the present invention, a chain transmission pulley is provided in which an outer peripheral surface is brought into contact with an inner peripheral side or an outer peripheral side plate side edge of a chain which is driven to travel along an endless traveling path to thereby provide a plate side edge. It is driven to rotate by friction with

The pulley is used by being fixed to an input shaft of equipment which operates in a light load and which is arranged in the vicinity of a traveling path of the chain, so that these equipment can be operated in conjunction with the traveling of the chain. Can be.

At this time, since the chain can be displaced in the width direction with respect to the outer peripheral surface of the pulley, the chain does not run out due to misalignment between the rotating shafts such as a sprocket. When the load acting on the input shaft of the device to which the pulley is attached increases, a slip occurs between the outer peripheral surface of the pulley and the plate side edge, thereby avoiding an overload condition.

Further, when the plate side edge is pressed against the outer peripheral surface of the pulley by the tension acting on the chain, the outer peripheral surface is elastically deformed so that the outer peripheral surface comes into close contact with the plate side edge. As a result, the shock at the time of contact between the plate of the chain running at high speed and the pulley is absorbed by the elastic deformation of the outer peripheral surface of the pulley, and the generation of noise due to the driving of the pulley is suppressed.

Further, in the chain driving pulley according to the third aspect, a flat side edge of a plate of the chain is supported in contact with each surface constituting a regular polygonal columnar outer peripheral surface of the pulley. Therefore, slip is unlikely to occur between the chain and the pulley, and since the plate and the outer peripheral surface of the pulley come into contact with each other over a wide area, the contact surface pressure is reduced, and uneven wear of the plate and the pulley is suppressed.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a side view of a chain transmission device used for an automobile engine, showing a first embodiment of a chain transmission pulley of the present invention. The chain transmission pulley is connected to a camshaft by a driving sprocket 1 connected to a crankshaft. The connected two driven sprockets 3 and 4 are driven via a silent chain (hereinafter simply referred to as a chain) 2.

The chain 4 includes a plurality of plates 2A having teeth formed on the inner peripheral side thereof for meshing with the sprockets 1, 3, and 4, and guide plates provided on both outer sides of these plates. 2B is a general silent chain in which a large number of pins 2C are connected by pins 2C, and the rear surfaces of these plates 2A and 2B facing the outer peripheral side of the chain 2 are formed as flat surfaces so as to be flush with each other. I have.

A tensioner 5 having a swingable tensioner lever 5A for preventing the chain 2 from loosening is provided outside the traveling path on the slack side of the chain 2. The tensioner lever 5A is provided with a tensioner main body 5B.
The tip of a plunger 5C, which is urged in the protruding direction and is protruded and retracted, is pressed from behind by the back, and the shoe surface facing the chain 2 slides on the flat back surfaces of the plates 2A and 2B of the chain 2. To apply an appropriate tension to the chain 2 to prevent its loosening.

On the other hand, on the tension side outer periphery of the chain 2, a chain transmission pulley (hereinafter simply referred to as a “pulley”) 6 of the present invention, which is fixed to an input shaft of a light-load accessory such as an oil pump or a water pump. And the pulley 6 is rotated by the traveling of the chain 2. The pulley 6 is made of a metal such as steel or cast iron, or a high-strength resin such as an engineering plastic.

As shown in FIG. 2 and FIG. 3, which is a partial cross-sectional view taken along the line AA of FIG. 2, the pulley 6 is fitted to the input shaft 7 of an auxiliary machine at the center and keyed. Shaft hole 6A
And a cylindrical outer peripheral surface 6C having an axial width H larger than the width h of the chain 2 on the outer peripheral side.
Rim portion 6D having

The outer peripheral surface 6C is in frictional contact with the rear surfaces of the plates 2A and 2B of the chain 2, and the pulley 6 is driven to rotate as the chain 2 travels. When the torque increases, a slip occurs between the rear surfaces of the plates 2A and 2B and the outer peripheral surface 6C of the pulley 6, and it is possible to prevent an overload from acting on auxiliary machines and the like.

FIG. 4 shows a second embodiment of the chain transmission pulley according to the present invention. The pulley 6 'of this embodiment has a central portion similar to that of the first embodiment described above. Has a boss portion 6'B formed with a shaft hole 6'A fitted to the input shaft 7 and keyed, and a rim portion 6'D on the outer peripheral side. The outer periphery of the rim portion 6'D is a cylindrical elastic layer mounting surface 6'C.
An annular elastic layer 6'E is fitted.

For the elastic layer 6'E, a material which can be easily elastically deformed, such as soft rubber, can be used. In this embodiment, portions other than the elastic layer 6'E are made of the same material as that of the first embodiment.

The outer peripheral surface 6'F of the elastic layer 6'E is formed in a cylindrical shape having a width wider than the width of the chain 2. However, the plates 2A, 2A,
2B, when they come into contact with the respective back surfaces, they are easily elastically deformed by receiving pressure from these back surfaces, and the portions of the outer peripheral surface 6'F that are in contact with the chain 2 are in close contact with these back surfaces, and the above-described structure is employed. The input shaft 7 can be driven with a larger torque than that of the first embodiment.

When an excessive load torque acts on the input shaft 7, the outer peripheral surface 6'F of the pulley 6 'is connected to the plate 2A of the chain 2 similarly to the first embodiment.
By slipping with respect to 2B, an overload condition is avoided. Further, the elastic layer 6'E has a function of absorbing vibration and impact when the elastic layer 6'E is in contact with the chain 2, thereby reducing the driving noise of the pulley 6 '.

FIG. 5 shows a third embodiment of a chain transmission pulley according to the present invention. The pulley 6 "of this embodiment is the same as that of the first embodiment described above and its outer peripheral surface 6". C
And a boss portion 6 "having a shaft hole 6" A formed at the center thereof to be fitted to the input shaft 7 and keyed.
B, and a rim 6 ″ D on the outer peripheral side.

In the pulley 6 "of this embodiment, the outer peripheral surface 6" C is formed in the shape of a regular polygonal prism having an axial width larger than the width of the chain 2, and the cross section thereof has a side length S adjacent thereto. The pitch is slightly smaller than the pitch P between the pins 2C of the matching chain 2 and is a regular polygon that fits the back surface of each plate 2A, 2B of the chain 2 bent along the outer periphery of the pulley 6 ″.

Accordingly, as shown in FIG. 5, when the chain 2 is bent along the outer peripheral surface 6 "C of the pulley 6 and passes, the plate 2A, 2A Since each back surface of 2B is pressed against a plurality of surfaces constituting an outer peripheral surface 6 "C of a regular polygonal column shape, a slip between the chain 2 and the pulley 6" is greater than that of the first embodiment. This hardly occurs, and the input shaft 7 can be driven with a large torque.

When the load resistance torque of the input shaft 7 increases, the outer peripheral surface 6C "
It is possible to prevent overload by slipping on A and 2B. In each of the above-described embodiments, the example in which the pulley is used to drive the light-load auxiliary equipment used in the engine with the silent chain has been described. However, the shaft of the light-load equipment is driven with a normal roller chain. In this case, the plate can be driven not only on the outer peripheral side but also on the inner peripheral side of the chain by bringing the plate into contact with the rollers.

In each of the above embodiments, the axial width of the outer peripheral surface of the pulley is set larger than the width of the chain in order to increase the transmission efficiency and stabilize the contact state with the chain. When the run-out during running is small, the width of both may be equal, and when a plurality of plates are arranged in the width direction of the chain like a silent chain and the contact area with the plate is large, The axial width of the outer peripheral surface of the pulley may be smaller than the width of the chain.

[0034]

As described above, according to the chain driving pulley of the present invention, a lightly loaded device can be driven to rotate on the outer or inner peripheral side of the chain plate.
In particular, since a silent chain with a flat plate back can be used to drive lightly loaded accessories such as oil pumps and water pumps on the outer periphery of the chain, the flat outer periphery of the chain can be used as a chain guide or tensioner lever. And the like, so that the chain can be prevented from swaying, so that the running noise can be reduced and the fatigue strength of the chain can be improved.

Further, since the outer peripheral surface of the pulley is driven by being brought into contact with the side edge of the plate of the chain, when the load torque increases, the pulley slips relative to the chain, and is driven to rotate via the pulley. And the like can be protected from overload, and there is no danger of tooth skipping or meshing noise occurring unlike a sprocket.

Further, since the power transmission is performed without depending on the meshing, the chain does not run out due to the misalignment of the rotating shaft. Furthermore, since the plate of the chain sequentially contacts the outer peripheral surface of the pulley without intervening to rotate the pulley, a conventional double-sided silent chain using a sprocket that meshes with the chain at every other pitch is used. The variation in chain tension can be reduced as compared with.

[Brief description of the drawings]

FIG. 1 is a side view of a transmission device using a silent chain in a first embodiment of a chain transmission pulley of the present invention.

FIG. 2 is a side view showing the first embodiment of the chain transmission pulley of the present invention.

FIG. 3 is a partial cross-sectional view taken along a line AA in FIG.

FIG. 4 is a side view showing a second embodiment of the chain transmission pulley of the present invention.

FIG. 5 is a side view showing a third embodiment of a chain transmission pulley of the present invention.

FIG. 6 is a schematic view showing an example of a chain transmission device using a conventional double-side mesh silent chain.

FIG. 7 is a schematic view showing another example of a conventional chain transmission device using a double-side mesh silent chain.

[Explanation of symbols]

 Reference Signs List 1 drive side sprocket 2 chain 2A, 2B plate 2C pin 3, 4 driven side sprocket 5 tensioner 5A tensioner lever 5B tensioner body 5C plunger 6, 6 ', 6 "pulley 6A, 6'A, 6" A shaft for chain transmission Hole 6B, 6'B, 6 "B Boss 6C, 6'F, 6" C, Outer peripheral surface 6'C Elastic layer mounting surface 6D, 6'D, 6 "D Rim 6'E Elastic layer 7 Input shaft

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor: Toyonaga Saito 4-17-96, Tsurumi, Tsurumi-ku, Osaka-shi, Osaka Inside Tsubakimoto Chain Co., Ltd.

Claims (3)

[Claims] 1. A chain transmission comprising a cylindrical outer peripheral surface which is driven to rotate in contact with a side edge of a plate of the chain on an inner peripheral side or an outer peripheral side of an endlessly circulated chain. Pulley. 2. The pulley for chain transmission according to claim 1, wherein said cylindrical outer peripheral surface is formed of a material which can be elastically deformed by a contact pressure received from a plate. 3. A regular polygonal column-shaped outer peripheral surface which is rotationally driven in contact with a flat plate side edge of the chain on an inner peripheral side or an outer peripheral side of a chain driven endlessly in circulation. Chain drive pulley.